Acid-catalyzed ring expansion of 1-(1-methoxy-1,2-propadienyl)-2-cyclobuten-1-ols. Synthesis of 5-hydroxy-5-vinyl-2-cyclopenten-1-ones and their stereoselective transformation to 5-(2-acetoxyethylidene)-2-cyclopenten-1-ones
Acid-catalyzed ring expansion of 1-(1-methoxy-1,2-propadienyl)-2-cyclobuten-1-ols. Synthesis of 5-hydroxy-5-vinyl-2-cyclopenten-1-ones and their stereoselective transformation to 5-(2-acetoxyethylidene)-2-cyclopenten-1-ones
Adducts from the radical addition of xanthates to ethyl vinyl sulfide readily undergo elimination of the xanthate group upon thermolysis to give vinylic and/or allylic sulfides, depending on the structure. In the case of α-xanthyl ketones, the adducts are converted into α-keto vinyl carbinols by rearrangement of the sulfoxides derived from the vinylic and allylic sulfides.
A Metallacycle Fragmentation Strategy for Vinyl Transfer from Enol Carboxylates to Secondary Alcohol C–H Bonds via Osmium- or Ruthenium-Catalyzed Transfer Hydrogenation
作者:Boyoung Y. Park、Tom Luong、Hiroki Sato、Michael J. Krische
DOI:10.1021/jacs.5b04688
日期:2015.6.24
A strategy for catalytic vinyl transfer from enol carboxylates to activated secondaryalcohol C-H bonds is described. Using XPhos-modified ruthenium(0) or osmium(0) complexes, enol carboxylate-carbonyl oxidative coupling forms transient β-acyloxy-oxametallacycles, which eliminate carboxylate to deliver allylic ruthenium(II) or osmium(II) alkoxides. Reduction of the metal(II) salt via hydrogen transfer
描述了从烯醇羧酸盐催化乙烯基转移到活化的仲醇 CH 键的策略。使用 XPhos 修饰的钌 (0) 或锇 (0) 配合物,烯醇羧酸盐 - 羰基氧化偶联形成瞬态 β-酰氧基 - 氧杂金属环,消除羧酸盐以提供烯丙基钌 (II) 或锇 (II) 醇盐。通过来自仲醇反应物的氢转移还原金属 (II) 盐,释放出甲醇 CH 乙烯基化的产物,并再生酮和零价催化剂。
STONE, GUY B.;LIEBESKIND, LANNY S., J. ORG. CHEM., 55,(1990) N5, C. 4614-4622